White anodic coatings are gained by growth in situ on the aluminum alloy. The coatings
possess stable optical properties, excellent adhesive power, low cost, stability in the space environment,
and so on, which can be widely used in the thermal control system of spacecrafts. In this article, the
developed Al2O3 thermal control coatings that had a low solar absorptance and a high infrared emittance
were gained in the electrolyte of sulfuric acid. The influences of various process parameters, such as
electrolyte temperature, current density, anodizing time, on the optical properties of the coatings were
investigated. AFM and XRD were used to characterize the microstructure of the coatings. Experimental
results show the anodic coatings could reach a solar absorptance value lower than 0.20 and an infrared
emittance higher than 0.80. Therefore, the coatings can be applied as important thermal control coatings
for space applications.
